Submission #1293488

#	Time	Username	Problem	Language	Result	Execution time	Memory
1293488		madamadam3	Cities (BOI16_cities)	C++20	37 / 100	6095 ms	38840 KiB

cities

#include <bits/stdc++.h>

using namespace std;
#define int long long int

using pi = pair<int, int>;
const int INF = 4e18;

signed main() {
    cin.tie(0)->sync_with_stdio(0);

    int n, m, k; cin >> n >> k >> m;
    vector<int> imp(k); for (int i = 0; i < k; i++) cin >> imp[i];
    vector<vector<pi>> adj(n+1, vector<pi>());
    for (int i = 0; i < m; i++) {
        int u, v, c; cin >> u >> v >> c;
        adj[u].push_back({v, c});
        adj[v].push_back({u, c});
    }

    vector<vector<int>> DP(1<<k, vector<int>(n+1, INF));
    for (int i = 0; i < k; i++) DP[1<<i][imp[i]] = 0;

    for (int mask = 0; mask < (1<<k); mask++) {
        for (int submask = mask; submask > 0; submask = ((submask - 1) & mask)) {
            int left = submask, right = mask ^ submask;
            if (left > right) continue; // evaluate each pair once

            for (int i = 1; i <= n; i++) {
                DP[mask][i] = min(DP[mask][i], DP[left][i] + DP[right][i]);
            }
        }

        for (int step = 0; step < n; step++) {
            for (int i = 1; i <= n; i++) {
                for (auto el : adj[i]) {
                    DP[mask][i] = min(DP[mask][i], DP[mask][el.first] + el.second);
                }
            }
        }
    }

    cout << *min_element(DP[(1<<k)-1].begin(), DP[(1<<k)-1].end()) << "\n";
    return 0;
}

• Subtask 1: 22 / 22
• Subtask 2: 0 / 14
• Subtask 3: 15 / 15
• Subtask 4: 0 / 23
• Subtask 5: 0 / 26